US2022994A - Mechanical stoker - Google Patents

Description

Dec. 3, 1935. J. B. M acKENZlE MECHANICAL STOKER Filed 001;. 9, 1928 2 Sheets-Sheet 1 m In W ii I I W WW mwm Dec.3, 1935. JBMMKENZIE 2,022,994

MECHANICAL STOKER Filed Oct. 9, 1928 2 Sheets-Sheet 2 of the tender, by bolts i1 Patented Dec." 3, 1935 PATENT "OFFICE MECHANICAL STOKER Joseph B. MacKenzie, Aspinwall, Pa.,

mesne assignments, to

assignor, by The Standard Stoker Company, Incorporated, a corporation of Delaware Application October 9, 1028, Serial No. 311,304 16 Claims. (01. -101 The invention relates to an appliance for feeding fuel to steam boilers, and is herein described as applied to locomotive boilers, although its ap- Dlication is not limited to that type of boiler.

The objects of this invention are, to make a stoker that will feed through the fire-door opening of a boiler without necessitating a change in size, design or location of the fire door: to make a compact design and one that will take up very -little room in the locomotive cab, which is already very crowded: to provide a stoker design, for locomotives, that can be used with a stationary trough in the tender: to furnish a stoker of simple construction with few movable parts, and these parts easily accessible.

The improvements claimed are hereinafter fully set forth.

In the accompanying drawings:

Figure 1 is a sectional view of the rear of the boiler and the front of the tender and stoker, on line i-l of Figure 4;

Figure 2 is a sectional view, taken through the fire-door opening on line 2-2 of Figure 1, showing the distributing plate which passes through the fire-door opening;

Figure 3 is a sectional view, taken on line 38 of Figure 1, showing the tender conveyor and central portion of the locomotive tender;

Figure 4 is a. plan view showing the stoker and driving engine with the fire-door box and guideplate removed;

Figure 5 is a rear view of the part of the stoker adjacent to the fire-door opening.

In Figure 1 a conveyor trough, I, is shown located below the coal space, 2, of the locomotive tender. An intermediate trough, 3, connects con veyor trough i with elevating conduit 4, rigidly mounted on the locomotive, and is flexibly con-- nected at 5 and 6 to the conveying trough and the elevating conduit respectively.

A helical conveyor screw, 1, is connected by universal joint 8 to intermediate screw 8.

Flexible connection 5 and universal joint 8 are to allow movement between the tender conveyor and intermediate trough. Flexible connection 6 is to allow movement between the intermediate trough and elevating conduit.

Intermediate conduit 3 is made in two pieces, l8 and I5; the forward piece, l5, moves .in and out in rear piece ill to allow for longitudinal movement between locomotive and tender.

Conveyor trough l is bolted to the floor, i6,

shown in Figure 3. Slide plates l8, of the type generally used, are

ing plate 3| movable on angles i9 and 20, which are mounted on the sides of the conveyor trough.

Transverse angles 2| form a connection between vertical angles 22 and 23 which support the tender deck. The transverse angles also 8 serve as stiffening members for the vertical anles.

Run-of-mine coal falls from the coal compartment, 2, through slide-plate opening 24 into the conveying trough and is carried forward by conveyor screw 1 through crusher 25, where the large lumps of coal are crushed to a size suitable for economic firing, to intermediate trough 3. Screw 8 conveys coal through intermediate trough to elevating conduit 4 and delivers it to screw 38 which, in turn, elevates it to distributin the fire-door opening.

The intermediate casing is provided at its front end with a pin connection, 32, which is located at its top, due to the fact that the end, 88, is

cut oil at a slant corresponding approximately to this type of flexible pin connection allows for a considerably longer intermediate conduit than 30 if a ball connection was. used on the frontend. The lower part 4| of the elevating unit is provided with a conduit receiving portion 88 having a substantially cylindrically shaped inside surface 81 arranged to receive a longitudinally convex enlargement 88 on the front end of the for-- ward intermediate section J8. The pin 82 extends through the receiving portion 88 of the lower part 4i and a hole 88 in the convex enlarged end 88 of the forward intermediate section I8, and has a shoulder 98 to prevent it from passing through the hole and disengaging the conduits. The hole 88 is smaller in diameter at the middle than at the inner and outer surface of the convex enlarged end 88 of the forward 45 intermediate section, which provides clearance is made in two pieces, 40 and 4|.

of the elevating conduit. A sealing device. 39, located in the bottom of the elevating conduit, prevents coal from getting into the worm-wheel case.

In stokers of this type it is general practice to support the stoker from the mud-ring of the boiler. In rthis case, however, the elevating unit The lower piece, M, is supported on the locomotive frame by a bracket, 42, and the upper piece, 40, is attached by means of flanges 43 and 44 to a filler piece, 45, which is, in turn, attached to the locomotive back-head adjacent -to the fire-door opening. The part carried on the frame is the heavier part, and by this method the weight carried by the boiler has been considerably diminished.

In order to allow for boiler expansion and the movement of the frame the lower section of the elevating conduit is provided at its top with a ring, 46, which is held. firmly against its upper surface by springs 41. This ring is slidable on the upper surface of the lowersection. The upper part of the elevating conduit fits inside this ring at 48 and is slidable therein.

It has been found on many locomotives that, when backing up against a long train in order to take up slack between the cars, the frame work is deflected upward. This movement of the frame and the expansion of the boiler are allowed for in the action of this ring on the top of the lower part of the elevator casing and its sliding on the outside of the upper part of the easing respectively.

The elevating screw is mounted loosely on the end of the driving shaft at 49, and the clearance between the screw flight and the conduit section 40 allows for lateral movement between the upper and lower portions of the elevating conduit.

In applying the stoker the lower portion of the elevating'conduit is located on the frame so that the rearward face of the screw touches the rearward wall of the upper part of the conduit. when the boiler expands and the upper portion moves backwards the screw will lie with its forward face against the forward wall of the upper conduit. The view in Figure 1 shows the location of the screw and the conduit when the boiler is hot and fully expanded.

The upper end, 50, of the elevating conduit, 4, changes from a round to a rectangular section, keeping the same area as in the circular part of the conduit. The longest sides of the rectangular outlet'opening at the 'top of the elevating conduit, 4 are disposed transversely of the locomotive. This change in the section of .the elevating conduit is made to allow the upper edge of the conduit to come closer to the' back-head of the boiler than has hitherto been possible. This construction decreases the distance that {he fire-door, 5|, must be moved from the backead.

The fire-door box or casing, 52, is attached to the filler piece, 45, by flange 53, and to the elevating conduit section or feed tube 40 by flanges 54 and 55. The fire-door, 5|, is supported on the fire-door box, 52, and rests on the lower edge in groove 56 on the upper part of the elevating conduit section 40.

The fire-door box, 52, provides a compartment, adjacent and exterior to the fire-door opening, into which the coal is delivered directly from the elevating screw: the box further provides a means for locating the fire-door back beyond-the point of elevation of the fuel.

It will be seen this box or casing has an open bottom mounted over the open top of the conduit section 4|]. Preferably, the top and side walls of .ward of the firebox wall and in a level below the 1 highest point along the bottom of the firing opening. The distributor plate 3| begins where the front wall ends and constitutes an extension thereof into the firing opening. As best shown in Fig. l, the rear and side walls of the conduit section 49 terminate in the same plane above the level of the upper edge of the front wall and the central portion of the distributor plate 3!. This construction aids in. advancing the fuel as soon as possible into the firing opening.

Taperlng the elevating screw, the conduit section 40 and the box or casing permits the firedoor to be located much nearer the backhead than would otherwise be possible.

If a straight elevator conduit were employed 2:; and the liredoor correspondingly moved back to suit, difficulty would be experienced in obtaining access to the firebox. With the construction disclosed the firedoor is so located that access to the firebox is not hindered.

Another advantage of the peculiar shape of the elevating conduit as a whole at its top portion is the fact that the coal is moving upward and into the fire-box at practically the entire width of the fire-door and thus a broad bank of coal is made to pass across the plate and fall in front of the distributing jets. This results in there being no dead coal space in the top of the elevator to accumulate coal where it would coke and stick fast to the firing plate. The fact that the 3 upper end of the conduit section 40 is the whole width of the fire-door opening and the fire-door causes a forward moving stratum of coal to pass across the distributing plate at all times.

Guide-plate 51 is mounted in the fire-door box'; and supported by trunnions 58 and 59 in the sides of the box. This plate is located just above the end of the elevating screw, and is for directing the coal toward the distributing 'plate, thus preventing the coal from being forced upward into 5 the fire-door box.

Another purpose of the guide-plate, 51, is to prevent the coal from piling up high enough to fall out of the fire-door should it be opened while the stoker is in operation.

The guide-plate, 51, is provided with a rod, 80. and crank mechanism, 6|, which is fastened to the worm-shaft, 62, to give a backward and forward or oscillatory motion which has the effect of pushing the coal forward on to the distribut- 60 ing portion of the plate.

It will be noted that the guide-plate, 51, can be readily turned out of the .way or can be dropped flush to provide for hand firing, thus leaving an unrestricted fire-door opening. This is accomplished by removing pin 63 and swinging plate by means of arm 64.

Distributing plate 3| is attached to the elevating casing at 65 and rests on the'lower surface of the fire-door opening on supporting ribs 66. These ribs keep the main body of the plate slightly above the lower surface of the fire-door opening and allow space for air to enter under the distributing plate, thus affording a cooling means to prevent the plate from becoming over- 7 2,022,994 heated. The outer edges 61 and 68 and the cen-,-

tral portion of the distributing plate are shaped to conform to the contour of the fire-door opening. This creates in longitudinal section an archlike formation of the plate over that portion of the firebox wall forming the lower extremity of the firing opening.

In the outer edges of the distributing plates are cored passages 69 and Ill communicating with cored passages H and 12 in the front of the plate. These passages are for applying fluid pressure to distributing jet holes 13 in the front face of the distributing plate. Pipes 14 and I admit the fluid pressure into the above mentioned cavities.

The pressure in the separate jet cavities is governed manually by means of valves in these pipes. The jet holes leading into cavity ll distribute the coal to the right-hand side of-the grate and, into cavity 12, to the left-hand side.

Providing these two cavities gives the fireman separate control over each half of the fire and,

by using more or less pressure, coal can be distributed to the front or back as he wishes.

As the coal is delivered from the end of the elevationg screw it is changed in its direction of fiow by the guide-plate, which deflects it inward onto the rear of the distributing plate from where it is pushed forward by the oncoming coal to the distributing table, I6, which lies in front of and below the distributing jets, and is here shown integral with the distributing plate: this construction, however, .is not necessary. The pressure required to force the coal to the distributing table is somewhat diminished, however,

due to the fact that the distributing plate slopes downward at its forward end and the coal will have a tendency to slide forward to the distributingtable due to the force of gravity and the vibration of the locomotive.

The driving engine, 11, is shown mounted on' the locomotive frame and drives the elevating unit through aflexible drive-shaft, 18, the driveshaft being driven from the motor through a bevel gear reduction, 19, these gears, in turn, being driven by worm and worm-wheel reduction enclosed in casing 80. The shaft and driving engine are both placed on the left hand side of the locomotive to enable the engine and worm gear casing to be cast integral.

The conveyor drive-shaft, 8|, driving the conveyor trough from the rear, is connected to the worm wheel reduction at 82. This form of construction eliminates thenecessity of a long intermediate shaft and housing between the driving engine and worm wheel case, which would be necessary if they were cast separately and located on opposite sides of the locomotive. This engine mounting and drive organization has been made the subject matter of a divisional application, Serial No. 722,087, filed April 24, 1934.

The cored passage, 83, extends along the upper rearward portion of the elevating conduit and communicates with jet holes 84. Fluid pressure is admitted through the cored passage to the jet holes. The jet holes extend inwardly and upwardly and are for removing the coal from above the elevating screw, thus allowing the fireman to lower the guide plate, 51, in order to have free access to the fire-door opening.

In ordinary running condition it is not necessary to use these jets, but when the stoker is stopped coal still lies between the guide-plate and the upper part of the elevator screw. With this condition it will be impossible to lower the guide-plate, but by using these jets this mass of coal is removed and leaves a free space into which the guide-plate may be dropped.

From the foregoing description it can be seen that a stoker of novel construction has been de- 5 vised which takes up much less room in the firedoor opening and in the locomotive cab than many of the existing designs, and is easily applicable to all locomotives.

I claim as my invention:

1. In combination with a locomotive having a firebox provided with a backhead having the conventional substantially oval shaped hand firing opening therein, a stoker conduit positioned exterior of the firebox and having a conveyor 15 screw therein delivering fuel to the lower portion of said opening, a distributor plate extending forward from the upper end of said conduit into said opening and conforming substantially to the shape of the lower edge of said opening, the sides of said plate curving upwardly to prevent fuel contacting with the sides of said opening, said plate being formed with passages in said side portions and with communicating transverse passages in its forward end portion hinged plate at the upper end of said conduit for moving the fuel discharged upward by said screw forward to said means, said plate being mounted at its lower end on. a fixed axis extending transversely and rearward of the upper extended axis 40 of said-- screw, power transmitting means operatively connected. with said screw at the base of said conduit comprising gearing and a rotatable shaft, and means operatively connecting said hinged plate with said shaft for'oscillating same. 3. In combination with a locomotive having a firebox provided with a backhead having the conventional hand firing opening therein, a stoker conduit mounted exteriorly of the firebox and arranged to deliver fuelto the lower portion of 60 said opening, and a distributor plate extending forward from theupper end of said conduit into and conforming substantially to the shape of the lower marginal portion of the opening and having side portions extending upwardly therein,

said plate being formed with passages in said side portions and with communicating transverse passages in its forward end portion and having jet openings communicating with the transverse passages arranged to issue pressure fluid jets forward of the upper end of said conduit. i

4. In combination with a locomotive having a firebox provided with" a backhead having a firing opening therein, a stoker conduit mounted exterior of the firebox and arranged to deliver fuel to the lower portion of said opening, a distributorplate extending forward from the upper end of said conduit into said opening, said plate having side .portions extending upwardly adjacent the sides of the firing opening to prevent fuel contactlng with the sides of said opening, and said plate being formed with a passage in at least one of said side portions and with a communicating transverse passage in its forward end portion and transverse passage arranged to issue fluid jets for-discharging fuel into the firebox.

5. In combination with a locomotive having a firebox provided with a backhead having a firing opening, an upright stoker conduit arranged centrally of the backhead exterior of the firebox, a conveyor screw within said conduit for deliv ering fuel to the lower portion of said opening, a chambered member at the lower portion of the firing opening having jet openings forward of the upper end of said conduit, a hinged plate at the upper end of said conduit, said plate being mounted at its lower end on an axis extending transversely and rearward of the upper extended axis of said screw, and means for oscillating said plate.

6. In combination with a locomotive having a firebox provided with a backhead having a firing opening, an upright stoker conduit arranged centrally of the backhead exterior of the firebox, a conveyor screw within said conduit for delivering fuel to the lower portion of said opening, a chambered member at the lower portion of the firing opening having jet openings forward of the upper end of said conduit for issuing fuel scattering pressure fluid jets; an inclined hinged plate atthe upper end of said conduit, said plate being mounted at its lower end on a fixed axis .extending transversely and rearward of the upper extended axis of said screw, said plate being spaced from said screw 2. distance sufficient to permit the fuel delivered by said screw to pass to said jets, and means rearward of the upper end of said screw arranged to issue a pressure fluid blast for discharging fuel from the space between said screw and saidplate.

7. In a locomotive having a frame and a firebox provided with a backhead, a stoker conduit disposed more nearly veitical than horizontal mounted adjacent the backhead and arranged to deliver fuel tosaid firebox, said conduit comprising a lower section attached rigidly to the frame of the locomotive and an upper section secured rigidly with the backhead, a screw extending within both of said sections for delivering fuel therethrough, said, screw being mounted in said lower section on a fixed axis and arranged in the upper section to provide a space between the edge of the flight of the screw and the inside surface of the upper section sufficient to permit the upper section to move with the backhead longitudinally with respect to said frame and laterally in respect to said screw when the backhead expands and contracts from the heat in the firebox.

8. In a locomotive having a frame and a firebox provided with a backhead, a stoker conduit disposed more nearly vertical than horizontal mounted adjacent the backhead and arranged to deliver fuel to said firebox, said conduit comprising a lower section attached rigidly to the frame of the locomotive and an upper section secured rigidly with the backhead whereby the upper section will move laterally with respect to the lower section when the backhead moves longitudinally on said frame due to expansion and contraction from the heat in the firebox, and a sealing member at the juncture of said sections movable with the upper section and slidably engaging the lower section. I 9. In combination, a firebox having an upstanding wall provided with a firing opening therein, a stoker conduit mounted exteriorly of the firebox and arranged to deliver fuel to the inside surface of the aforesaid firebox wall, transverse passages in the forward portion of said plate, said face being provided with a plurality of jet holes communicating with said transverse passages and said side portions each having a.

passage communicating with one of said transverse passages, and a distributing table within the firebox extending forwardly from said face below the jet holes therein.

10. In combination, a firebox having an upstanding wall provided with a firing opening therein, a stoker conduit mounted exteriorly of the firebox and arranged to deliver fuel to the lower portion of said opening, a plate-like distributor member extending forward from the upper end of said conduit into said firing opening and conforming substantially both in transverse and longitudinal sections tothe shape of the lower edge of said opening, said plate member having upwardly extending side portions within the opening and including a transverse front face directed inwardly of the firebox adjacent the inside surface of the aforesaid firebox wall. said face being provided with a plurality of jet holes and said side portions each having a passage and means providing communication between each 3 passage and certain of said jet holes, and a distributing table within the firebox extending forwardly from said face below the jet holes therein I and in a level below the highest point on the surface of that portion of the firebox wall defining the lower extremity of the firing opening considered on the vertical medial plane-of said firing opening longitudinally of the firebox.

11. In combination, a firebox having an upstanding wall provided with a firing opening 5 therein, a stoker conduit mounted exteriorly of the firebox and extending from a point below upwardly to said firing opening and arranged to deliver fuel thereto, said conduit having a front wall the centrally disposed fuel supporting surface of which at its upper edge terminates rearward of the firebox-wall and below the highest point on the surface of that portion of the firebox wall defining the lower extremity of the firing opening considered on the vertical medial plane of said firing opening longitudinally of the firebox, a distributor member extending upwardly,

from said upper edge of the front wall and forwardly into the firing opening closely adjacent the aforesaid lower marginal edge thereof and thence sloping downwardly and inwardly toward the inside of the firebox, said distributor member constituting a fuel supporting extension of said front wall and having a transverse front face adjacent the inside surace of the firebox wall pro- 55 vided with a plurality of jet openings, said distributor member including a passage communieating with said jet holes and having an opening directed exteriorly of the firebox for the introduction of pressure fluid, and adistributing table within the firebox extending forwardly from said face below said jet holes and in a level below said highest point in the surface of that portion of the firebox wall defining the lower extremity of the firing opening.

12. In a stoking apparatus, the combination with a firebox having an upstanding wall with a firing opening therein, a door casing connected to said upstanding wall having top and side walls surrounding corresponding portions of the firing opening, a door movably mounted on said casing, said door being disposed in spaced relation to said firebox wall and forming arear wall portion of the casing, a conduit for delivering fuel upwardly through the lower portion of the casing to said firing opening, said conduit having front, rear and side walls, the rear and side walls terminating in substantially the same plane in a level above the upper edge of the front fall, said side walls having portions disposed in abutting relation to the side walls of the casing, said door constituting a continuation of the rear wall of the conduit, and a distributor member disposed in said firing opening at the upper end of said front wall of the conduit, said distributor member having a portion of its upper surface centrally of the firing opening positioned below the level of the aforesaid terminal plane of the rear and side walls of the conduit.

13. In a stoking apparatus, the combination with a firebox having an upstanding wall with a firing opening therein, a door casing connected to said upstanding wall having top and side walls surrounding corresponding portions of the firing opening, a door movably mounted on .said casing, said door being disposed in spaced relation to said firebox wall and forming a rear wall portion of the casing, a conduit for delivering fuel upwardly through the lower portion of the casing to said firing opening, said conduit having front, rear and side walls, the rear and side walls terminating in substantially the same plane in a level above the upper edge of the front wall, said side walls having portions disposed in abutting relation to the side walls of the casing, the said door of the casing constituting a continuation of the rear wall of the conduit, said front wall of the conduit terminating rearward of the firebox wall, and a distributor member extending upwardly from the upper edge of said front wall and curving forwardly into the firing opening, said distributor member constituting an extension of said front wall and having a portion of its upper surface centrally of the firing opening positioned in a level below the aforesaid terminal plane of the rear and side walls of the conduit.

14. In a stoking apparatus, the combination with a firebox having an upstanding wall with a firing opening therein, a door casing connected to said upstanding wall having top and side walls surrounding corresponding portions of the firing opening, a door movably mounted on said casing, said door being disposed in spaced relation to said firebox wall and forming a rear wall portion of the casing, a conduit for delivering fuel upwardly through the lower portion of the casing to said firing opening, said conduit having front, rear and side walls, the rear and side walls terminating above the level of the upper edge of the front wall and said side walls having portions disposed in abutting relation to the side walls of the casing, said door constituting a continuation of the rear wall of the conduit and said front wall of the conduit terminating rearward of the firebox wall, and a distributor member extending upwardly from the upper edge of said front wall and curving forwardly into the firing and a casing disposed above and having an open 1 bottom in communication with the open top of said feed tube, said casing being connected to the firebox wall and having top and side walls surrounding corresponding portions of the firing opening, the plane of the outer marginal edges of said top and side walls being spaced from the firebox wall and inclined downwardly and rearwardly from said wall in the general plane of the inclined feed tube which is inclined forward and upward from a point below the firing opening, said feed tube having front, rear and side walls, the front wall at its upper end terminating adjacent the lower marginal portion of the firing opening and rearward of the firebox wall and the rear wall terminating in a plane above the upper edge .of said front wall, the side walls of said casing constituting laterally spreading continuations of the side walls of said feed tube and the said outer edges of the top and side walls of the casing and the upper edge of said rear wall of the feed tube defining an opening in said casing in substantial register with said firing opening, a movable door forming a closure for the opening in said casing and constituting a continuation of the rear wall of the feed tube, and a distributor member extending upwardly from the upper edge of said front wall of the conduit and curving forwardly into the firing opening, said distributor member constituting an extension of said front wall of the conduit and having a portion of its upper surface centrally of the firing opening positioned in a level below the upper edge of the-rear wall of the conduit.

16. In combination, a firebox having an upstanding wall provided with a firing opening therein, stoker conduit means mounted exteriorly of the firebox and extending from a point below upwardly to said firing opening and arranged to deliver fuel thereto, said conduit means having a wall the central fuel supporting surface of which extends to the firebox wall and which conduit wall at a point below the highest point on the surface of that portion of the firebox wall defining the lower extremity of the firing opening considered on the vertical medial plane of said firing opening longitudinally of the firebox then slopes forwardly and upwardly into said firing opening closely adjacent the aforesaid lower extremity thereof and thence sloping downwardiy and inwardly toward the inside of the firebox, and means at the end of the aforesaid downwardly and inwardly sloping portion of said conduit wall for propelling the fuel over the firebed of the firebox including forwardly directed jet holes disposed infa level below the highest point of the central portion of that part of said conduit wall within the firing opening, and a distributor table positioned below the level of said jet holes.

JOSEPH B. MACKENZIE.

Images